The present invention relates to a clip-type lead frame and an electric device with two substrates electrically connected by the lead frame.
Conventionally, there have been proposed a number of clip-type lead frames for electrically connecting a main substrate with a sub-substrate or semiconductor device provided on the main substrate. For this purpose, each of the proposed clip-type lead frames has pairs of clip-type lead pins. The paired lead pins are so sized and shaped that they clip and hold the sub-substrate or semiconductor device and, simultaneously, make contacts with corresponding connection pads, if any, provided on a periphery of the sub-substrate or semiconductor device.
For example, a variety of clip-type lead frames have been proposed in Japanese Patent Laid-open Publication Nos. 7-320801, 7-230837, 9-83132 and 5-101854 and Japanese Utility Model Laid-open Publication Nos. 2-8877 and 2-88248. Typically, each of the lead frames proposed in the applications has a specific structure similar to that described in FIG. 9.
Referring to FIG. 9, a memory board 100 or sub-substrate mounted on a main-substrate 200 by means of clip-type lead frames 110 and 120 of the same size and structures. For clarity, electric wires provided on the main-substrate 200 are omitted from the drawing. The memory pad 100 supports connection pads 102, 104 and 106 on a peripheral portion of its upper surface and another connection pads 101, 103, 105 and 107 on the opposite peripheral portion of its lower surface at regular intervals.
As can be seen from the drawing, the clip-type lead frame 110 or 120 has lead pins 121-127 corresponding to connection pads 101-107 provided on the upper and lower peripheral portions of the memory board 100. The lead pins 121, 123, 125 and 127 are provided in places corresponding to the lower connection pads of the memory board 100. The lead pins 122, 124, 126, on the other hand, are provided in places corresponding to the upper connection pads of the memory board 100. A vertical gap between the lower and upper lead pins is determined so that, when once engaged with the memory board 100, they clip and then hold the memory board 100.
However, the vertical gap between the upper and lower pins is fixed, which makes it impossible to apply one lead frame for various semiconductors or sub-substrates having different thicknesses.
Therefore, a purpose of the present invention is to provide a clip-type lead frame having flexibility to several boards with different thickness caused by not only an uneven product quality but also several different type products.
To this end, a clip-type lead frame for mounting a first substrate with connection pads on its peripheral portion on a second substrate, comprising: a support made of electrically insulative material; and a first pin and a second lead pin made of electrically conductive material and mounted in the support so that an upper portion of first lead pin opposes to an upper portion of the second lead pin with leaving a gap therebetween for clipping and holding the first substrate, wherein at least one of the first and second lead pins has a mechanism for adjusting the gap between the opposing upper portions of the first and second pins.
In another aspect of the present inventions, the upper portions of the first and second lead pin are positioned so that the upper portion of the first lead pin makes a contact with an upper surface of the first substrate and the upper portion of the second lead pin makes a contact with a lower surface of the first substrate, and wherein the adjust mechanism is provided to the first lead pin.
In another aspect of the present inventions, the upper portions of the first and second lead pin are positioned so that the upper portion of the first lead pin makes a contact with an upper surface of the first substrate and the upper portion of the second lead pin makes a contact with a lower surface of the first substrate, and wherein the adjust mechanism is provided to the second lead pin.
In another aspect of the present inventions, the mechanism comprises an upper part of the lead pin, a lower part of the lead pin separated from the upper part of the lead pin, and a holder defined in one of the upper part and the lower part of the lead pin for holding the other of the upper part and the lower part of the lead pin. Also, the remaining part of the of the lead pin has a deformation for preventing a slip between the upper part and the lower part of the lead pin. Preferably, the deformation may be a corrugated portion.
In another aspect of the present inventions, the mechanism has an angled section.
In another aspect of the present inventions, the support has an insulating portion which opposes to a peripheral portion of the first substrate held between the first and second lead pins.